Vertically pivoted windows are commonly used in commercial buildings where windows are not used for routine ventilation but for transmission of light and for decorative purposes. In normal use, the windows are held securely in a closed position at a number of locking points. On large pivot windows, multiple locking points are required. To ensure a tight seal, a tall window sash will require locking points which are substantially elevated above the floor. These elevated locking points require an operator to mount a stool or ladder to open the window. Although the vertically pivoted window will remain closed throughout much of a year, it must be opened occasionally for emergency ventilation and for routine cleaning of the window panes.
Conventionally, each locking point requires a separate key for opening the lock. For ease of operation and convenience, a mechanism is needed for vertically pivoting windows which allows safe and economical operation of multiple locking points without the operator leaving the floor.